Refractory wall construction



Sept. 27, 1966 w. BVPAUL, JR, ETAL 3,274,742

REFRACTORY WALL CONSTRUCTION Filed Feb. '7, 1963 4 Sheets-Sheet 1 INVNTOR5 g g4 ,z Ah I Sept; 27, 1966 w. B. PAUL, JR., ETAL 3,274,742

REFRACTORY WALL CONSTRUCTION 4 Sheets-Sheet 2 Filed Feb. 7, 1963 l NV$2.5 5

Se t. 27, 1966 w. B. PAUL, JR., ETAL 3,274,742

REFRACTORY WALL CONSTRUCTION Filed Feb. 7, 1963 I 4 Sheets-Sheet 5 p 7,1966 w. 5. PAUL, JR., ETAL 3,274,742

REFRACTORY WALL CONSTRUCTION Filed Feb. '7, 1963 4 Sheets-Sheet 4.

United States Patent 3,274,742 REFRACTORY WALL CONSTRUCTION Wortley B.Paul, Jr., Berwyn, Pa., and George C. Mayhew, Dearborn, Mich, assignorsto General Refractories Company, Philadelphia, Pa., a corporation ofPennsylvania Filed Feb. 7, 1963, Ser. No. 256,922 3 Claims. ((31.52-245) The present invention relates to refractory Walls which areinclined to the horizontal and to the vertical, to methods forassembling and constructing such refractory walls, and to refractorybrick, particularly burned basic refractory brick, for use in suchrefractory walls.

A purpose of the invention is to reduce the danger to masons ininstalling inclined refractory walls of burned refractory brick,particularly conical refractory walls, and especially such walls inbasic oxygen furnaces or L/D converters.

A further purpose is to reduce the cost of installation of inclinedrefractory walls of burned refractory brick, particularly conicalrefractory walls in basic refractory furnaces or L/D converters.

A further purpose is to provide a metallic projection on a burnedrefractory brick.

A further purpose is to eliminate the need for using retaining formsduring the construction of such walls.

A further purpose is to avoid the harmful effect on refractory life dueto corbelling.

A further purpose is to hold the course of a burned refractory brick ofan inclined refractory wall during installation and before it has beenkeyed in place and also during service by providing a metallicprojection at the cold end transverse to the length of the brick andextending downward behind the cold end of the refractory brick of thenext lower course, desirably also providing a space at the cold end ofthe refractory brick of the next lower course to receive the metallicprojection.

A further purpose is to mount the construction on skewbacks and to holdthe first course above the skewbacks by metallic projections engagedbehind the skewbacks.

Further purposes appear in the specification and in the claims.

In the drawings we have chosen to illustrate a few only of the numerousembodiments in which the invention may appear, selecting the forms shownfrom the standpoints of convenience in illustration, satisfactoryoperation, and clear demonstration of the principles involved.

FIGURE 1 is a perspective of one embodiment of refractory brickaccording to the invention, suitably illustrating a key arch brick.

FIGURE 2 is a perspective of the brick of FIGURE 1 shown from theopposite side.

FIGURE 3 is a fragmentary enlarged section on the line 3-3 of FIGURE 1.

FIGURE 4 is a vertical axial section partly in phantom of a basic oxygenfurnace or an L/D converter having a refractory wall according to theinvention.

FIGURE 5 is an enlarged fragment of FIGURE 4 as indicated by the circle5 on FIGURE 4.

FIGURE 6 is an enlarged fragmentary section on the line 66 of FIGURE 5.

FIGURE 7 is an enlarged elevation of the hot ends of the bricks ofFIGURE 7, the view being in the position indicated by the line 77 ofFIGURE 5 and exaggerated for convenience in illustration.

FIGURE 8 is an enlarged elevation of the outside of the wall of FIGURE5, in the position indicated by the line 88, and exaggerated for ease inillustration.

FIGURE 9 is an enlarged fragmentary section on the line 9-9 of FIGURE 6.

FIGURE 10 is a view similar to FIGURE 8 but illustrating a differentposition of the metallic projections of the upper course with respect tothe joints in the lower course.

FIGURE 11 is a perspective of a key arch skewback brick as shown inFIGURE 5.

FIGURE 12 is a perspective of a top course brick as shown in FIGURE 5.

FIGURE 13 is a perspective showing the metallic projection beforeinsertion in the brick.

FIGURE 14 is a perspective of a brick showing the metallic projectioninserted in a recess in the brick.

FIGURE 15 is a plan view of the metallic projection of FIGURE 14 beforebending.

FIGURE 16 is an elevational view of the projection of FIGURE 15.

FIGURE 17 is a right end elevation of the projection of FIGURE 16.

FIGURE 18 is an enlarged fragmentary top plan view of the brick ofFIGURE 13 showing the insert in the brick recess.

FIGURE 19 is a vertical section taken on the line 1919 of FIGURE 18.

Describing in illustration but not in limitation and referring to thedrawings:

In refractory construction at the present time, there are a number ofplaces where walls are used which are inclined both to the vertical andthe horizontal. A very good example is the basic oxygen furnace whichhas such an inclined wall construction of generally conical form nearthe upper part.

It has been familiar practice to construct such inclined walls by usinga corbelled construction, in which the in ner and outer surfaces are ofsaw-tooth contour consisting of a separate step for each course ofbrick, the courses themselves being laid horizontally and with overlap.This has the objection, however, that the refractory life is greatlyreduced due to the increased surface exposed to the furnace interior.Where an attempt has been made in corbelled construction to render theinner surface flush by feather-edging the hot end, the sawtooth contourremains at the cold or outer end.

In this corbelled construction, the cold ends of the refractory lackstructural stability when the portion of the lining becomes thin, sothat the refractory wall has a greater tendency to collapse.

Efforts have been made in Europe, Canada and the United States toeliminate the corbell and produce a continuous inclined surface at thehot face of the wall by making the longitudinal axes of the brickperpendicular to the hot face of the wall. This has resulted inincreased refractory life.

In one procedure for building such walls, it has been suggested that aform be used which holds the brick in place during construction. This isexpensive and also dangerous, since the masons are subject to thepossibility of serious injury if the form should break before the wallbecomes self-supporting. This is also only applicable to a wall which isof closed contour and therefore would become self-supporting.

Efforts to construct many wall portions without a form are highlydangerous, since the slope often is greater than will permit a brick tosupport itslef in inclined position (limited to about 22 degrees).

The present invention is designed to permit the construction ofrefractory walls inclined both to the horizontal and the vertical at:any desired angle with smooth interior surfaces free from corbelling.

One of the great advantages of the present invention 3 is that it is notnecessary to use forms but, on the other hand, the masons can work insafety.

Another great advantage of the invention is that the cost ofinstallation in view of the subsequent lining performance obtained is soreduced that the overall refractory cost of a basic oxygen furnace orL/D converter can be reduced by as much as 20% In a copendingapplication of Paul, Serial No. 222,289 for Refractory WallConstruction, Brick and Method, filed September 10, 1962, now abandonedand of common ownership herewith, a refractory brick and wall is setforth wherein each refractory brick of an upper course is provided witha metallic projection comolded with the brick at the cold end transverseto the length of the brick and this metallic projection is fitted behindthe brick of the lower course. This is satisfactory for an unburnedrefractory brick, but where it is necessary to use a burned refractorybrick, such as in the safety lining of a conical section of a basicoxygen furnace, the heat of burning destroys the metallic projection. Bya burned refractory brick, it is meant a brick which is .first moldedand then subjected to high temperatures before installation in a furnacelining.

In accordance with the present invention, each burned refractory brickof an upper course is provided with a metallic projection at the coldend transverse to the length of the brick which is installed on thebrick subsequent to the burning operation. In one form of the invention,a metallic tab is fixed to the cold end of the brick so that a portionof the tab extends transversely beyond the cold end. In another form ofthe invention a recess is molded in the brick and a metallic tab isinserted in the recess subsequent to the burning of the brick and thismetallic projection is fitted behind the brick of the lower course,which may be either a skew or another one of the brick just described.

While the invention is applicable to any desired form of inclinedrefractory wall, it will find its greatest advantage in an inclinedrefractory wall of conical or other closed configuration, especially ofthe type employed in a basic oxygen furnace or L/ D converter.

' The refractory in the present invention can be assembled completelywithout retaining forms, and at the same time the danger formerlyencountered by the masons is no longer present.

Considering first the forms as shown in FIGURES 1 to 9, we thereillustrate a basic oxygen furnace or L/D converter 20 having a metallicshell 21 which receives a more or less permanent refractory safetylining 22 suitably of burned magnesite refractory and a refractorylining proper 23.

For purposes of illustration, both the glued tab embodirnent of theinvention and the metallic tab insert embodirnent will be shown appliedto the refractory lining proper 23. However, it should be understoodthat either form may be used on either the safety lining or the workinglining and the principles of the invention are equally applicable toboth. Furthermore, in some instances, it may be preferable to use theglued embodiment on the safety lining and the insert embodiment on theworking lining or vice versa.

It should be further understood that where reference is made torefractory bricks, these may be bricks of the safety lining or bricks ofthe working lining.

The refractory lining proper 23 comprises a bottom portion 24 which maybe of any conventional character,

a cylindrical side wall portion 25 which likewise may be of anyconventional character, and an inclined conical portion 26 whichconforms to the present invention and rests upon the cylindrical sidewall portion 25- The refractory may consist of 50% by weight of coarsedead burned magnesite particles suitably in the size range between 6 and28 mesh per linear inch and 50% by weight of fine dead burned magnesiteparticles in the size range through 48 mesh per linear inch. Othercombinations of particles of suitable size may be employed as desired.

The conical inclined Wall portion has a lower course of skews 27 whichare best seen in FIGURES 5 and 11 and which are desirably key arch skewsof a character which have not heretofore been used. Considering theircross section as shown in FIGURE 5, they consist of a hot end 28 whichconforms to the slope of the inclined wall, a cold end 30 which isparallel to the hot end except for the recess to be described, and alower cold end portion 31 which is horizontal in assembly, making anangle at 32. There is a horizontal bottom face 33 which rests on the topof the cylindrical wall portion 25 and there is an inclined top surface34 which is at right angles to the inner inclined face 28 of the wallportion 26.

Unlike the usual skewback, however, the side faces which are not shownin FIGURE 5 but which are ShOtWIl in FIGURE 11 are peculiar, giving thekey arch character to the skews. Like a skew brick, the side faces 35are converging toward the interior of the furnaces so that the hot faceis narrower than the cold face and they also are converging upwardly sothat the top face 34 is narrower than the cold face of the skew.

These skews are put in to make a complete circle or other endless figurein plan view, if necessary fitting in a specially cut brick or applyingmortar to complete a tight fit.

Each of the skews at the upper portion of its cold face 30 has a recess36 parallel to the hot face 28 and wide enough in the direction towardthe hot face to receive a metallic projection 37 to be described.

In some instances, it may be desirable to eliminate the recess 36, andin this case, spaces at the cold end of the skewbacks to receive themetallic projections are formed by applying a coating of mortar overpart of the cold face.

Suitably when the course of skews has been completed, the next course ofbricks 38 are applied. Since the course of bricks 38 above the skewsresemble each of the other courses, except at the top, it will besufiicient to describe one of these upper courses 38. Each of the bricksof this upper course 38 as shown at 40 has a hot end 41 which extendsinto the furnace in direct prolongation of the hot end of the wall 35and has a cold end 42 which is in principle parallel to the hot end 41.

' Each' of the bricks 40 has a bottom surface 43 and a top surface 44which are suitably parallel as shown. Each of the bricks 40'also hasside surfaces 45, and as the bricks are key arch bricks in the preferredembodiment, the side surfaces 45 converge toward the hot end so that thecold end has a larger surface than the hot end. The bricks 40 alsoconverge upwardly so that the upper surface 44 is smaller than the lowersurface 43.

While the use of bricks of this particular character is preferred in thepresent embodiment, it will be understood that for many aspects of theinvention, advantages will be obtained by simply using key brick orsimply using arch brick or simply using :arch brick without necessarilyusing key arch brick.

The longitudinal extent of the brick, or the length, is from the coldend to the hot end. At the cold end, each of the bricks has extendingtransverse to its length or at right angles to its bottom surface 43 ametallic projection 37.

The projection 37 in one form consists of a flat metallic sheet which isattached to the cold end of the brick by a strong adhesive 39'. An :area42' is left uncovered at the cold end of the brick so that a spacebetween the brick and the safety lining can be formed on a lower formedin Z shape as shown in FIGURE 13. One leg 37 of the Z is intended toprotrude transverse to the cold end of the brick as shown in FIGURE 14.Another leg 37 of the Z is intended to enter a recess 39 comol'ded inthe brick. The recess is shown as a partial truncated inverted cone inshape, but it may be of cylindrical or other form.

The leg 37 has a flat portion 37 and rounded edges 37 curved to suitablyfit the contour of recess 39 when slightly compressed. A web 37 isintended to lie along face 43 of the brick. The web 37 lies in a recess43 in face 43 so that the top surface of the web 37 is flush with theface 43 as best seen in FIGURE 19. The projection 37 is suitably drivenor otherwise inserted into recess 39 after the brick has been subjectedto burning and before the brick is installed in the wall. Preferablyinclined recesses 42' are InOllCiBd in the brick to receive portion 37(from an upper course of brick as later explained.

The size of the steel sheet used in the projections 37 and 37 is to bedetermined by the size of the brick shape involved and can range inthickness between 16 gage to 22 gage as required.

In installing the course of brick 38, the metallic projection 37 ishooked into the recesses 36 of the skewbacks or the space formed by themortar coating and the complete ring of the course 38 is preferablycompleted and keyed into place.

Subsequently courses then resemble the installation of the course 38,except that the metallic projections are engaged in the spaces 42' whenusing insert 37 or the spaces 46 fonrned by the previous course ofbricks when using the adhesively applied projections 37, instead ofrecesses of the skewbacks. The spaces 46 are formed at portion 42 of thecold end of the brick 42 not occupied by the tab 37.

The topmost course 51 is of suitable shape to render the mouth of thefurnace lining level with the mouth of the furnace shell. The brick 52used in the topmost course 51 is shown in FIGURE 12. The brick has alower inclined face 53 which conforms to and rests upon the lower courseof bricks 38. The hot face 54 is flush with the inclined conical portion26. The top face 55 is so disposed as to be level with the top of theshell when the brick is put in place. The face 56 is in a plane normalto the plane of the face 55. Face 56 is so disposed in order to providethe proper critical dimension across the mouth opening.

Opposed faces 57 and 58 are disposed at an angle toward one anothercompatible with the furnace diameter at that elevation. Outer face 60conforms to the shell contour.

It will be evident that the location of the joints in the upper coursewith respect to the joints in the lower course will depend to someextent upon the preference of the installer. Thus, if desired, thejoints can be staggered as shown in FIGURE 8, in which case theprojections 37 of one brick will in some instances engage behind twobricks of the lower course. On the other hand, the joints can be in lineas shown in FIGURE as preferred.

The principles of the invention are applicable regardless of thecomposition of the refractory bricks, and while burned basic magnesiterefractories have been selected, it will be understood that other burnedrefractories, especially other burned basic refractories, may be used.

Although the embodiments of the invention have been illustrated on therefractory lining proper 23, it should be understood that the inventionmay be applied with equal results on the safety lining 22.

In view of our invention and disclosure, variations and modifications tomeet individual whim or particular need will doubtless become evident toothers skilled in the art, to obtain all or part of the benefits of ourinvention without copying the method and structure shown, and We,therefore, claim all such insofar as they fall within the reasonablespirit and scope of our claims.

Having thus described our invention what we claim as new and desire tosecure by Letters Patent is:

I. An inclined conical refractory wall comprising burned refractorybricks laid in conical course, each brick having a hot end and a coldend with sides extending longitudinally between the ends, the hot endforming an inner inclined conical wall surface with a cold end beingsubstantially parallel thereto, said wall including a lower course ofbricks and an upper course of bricks resting directly on the lowercourse of bricks, each brick of an upper course having an aperture inthe lower side of the brick and a metallic projection, the projectioninciuding a tab extending downwardly from the cold end of the brickperpendicular to the lower side of the brick adapted to engage againstthe cold end of a brick of a lower course, a web extending inwardlytherefrom along a recess in the lower side of the brick toward the hotend and a leg extending upwardly from the web parallel to the tab andresiliently wedged into the aperture in the lower side of the brick.

2. An inclined refractory wall according to claim 1, wherein the outersurface of the tab is flushed with the cold end surface of the brick,each brick additionally including a recess extending from the top of thecold end of the brick downwardly a part of the distance to the lowerside of the brick, the recess adapted to receive the tab of the metallicprojection of a brick of an upper course.

3. An inclined conical refractory wall according to claim 1, wherein thelowermost course of bricks are comprised of skewback bricks having a hotend conforming to the inclined conical wall surface, a lower sidesubstantially horizontal at an upper side substantially perpendicular tothe inclined wall surface and an uppermost course of bricks having alower side substantially perpendicular to the inclined wall surface andan upper surface substantially horizontal.

References Cited by the Examiner UNITED STATES PATENTS 495,411 4/ 1893Heatley 5 2-609 829,234 8/1906 Seipp 52704 1,648,363 11/1927 Reintjes-99 1,913,168 6/1933 Longenecker 110-99 2,319,065 5/ 1943 Karmanocky110-99 2,695,257 11/ 1954 Castellani 161156 2,885,976 5/1959 McGill et'al 110-99 2,915,893 12/1959 Wilkins 110-99 3,005,424 10/ 1961 Heuer110-99 FOREIGN PATENTS 85,213 3/1958 Denmark. 638,767 6/1950 GreatBritain.

FRANK L. ABBOTT, Primary Examiner.

HENRY C. SUTHERLAND, Examiner.

J. L. RIDGILL, Assistant Examiner.

1. AN INCLINED CONICAL REFRACTORY WALL COMPRISING BURNED REFRACTORYBRICKS LAID IN CONICAL COURSE, EACH BRICK HAVING A HOT END AND AN COLDEND WITH SIDES EXTENDING LONGITUDINALLY BETWEEN THE ENDS, THE HOT ENDFORMING AN INNER INCLINED CONICAL WALL SURFACE WITH A COLD END BEINGSUBSTANTIALLY PARALLEL THERETO, SAID WALL INCLUDING A LOWER COURSE OFBRICKS AND AN UPPER COURSE OF BRICKS RESTING DIRECTLY ON THE LOWERCOURSE OF BRICKS, EACH BRICK OF AN UPPER COURSE HAVING AN APERTURE INTHE LOWER SIDE OF THE BRICK AND A METALLIC PROJECTION, THE PROJECTIONINCLUDING A TAB EXTENDING DOWNWARDLY FROM THE COLD END OF THE BRICKPERPENDICULAR TO THE LOWER SIDE OF THE BRICK ADAPTED TO ENGAGE AGAINSTTHE COLD END OF A BRICK OF A LOWER COURSE, A WEB EXTENDING INWARDLYTHEREFROM ALONG A RECESS IN THE LOWER SIDE OF THE BRICK TOWARD THE HOTEND AND A LEG EXTENDING UPWARDLY FROM THE WEB PARALLEL TO THE TAB ANDRESILIENTLY WEDGE INTO THE APERTURE IN THE LOWER SIDE OF THE BRICK.